Method for the separation of chemically modified rosins and their esters into components



Patented Feb. 1940 eATENro -Fici:

" This inventionrelates to a method for the seiziaration of chemically modified rosins and their esters into components; and more particularly the separation of chemically modified rosinsand their esters into components by treatment with aselective solvent. 1

Due to the complexity of thechemical am;

' ture of rosin, treatments for theproduction of chemical modifications practically always result 1 in -products which are mixtures of two or more chemical compounds. ,The product may contain I unchanged rosin or the rosin may be' converted into two or more 'difierent materials, orb'othfiThe esterification of such a modified product produces a modified'r'osin ester which, similarly, is ainixture of chemically different esters. Likewise, esterification of rosin and then treatmentto'produce chemical modification, gives a product which" isa mixture of chemically different esters. 0 Thus, for example, the hydrogenation of rosin may result' in a mixture of unchanged rosin and dihydro-rosin. More complete hydrogenation'results in a mixture of dihydro---'rosin and tetra hydro-rosin." The production of a product which 5 is entirely tetrahydro-rosinhas so far provedim' possible; The esterifi cation of. a hydrogenated immiscible therewith,separatingthe two solutions thus formed, and recovering a component of the modified rosin or modified rosin ester'from each rosin results in a mixture of rosin esters. Like= wise, thehydrogenation of rosin esters results in a mixture of ordinary rosin ester *and' dihydrorosin ester or a mixture of dihydro-rosin ester and-tetrahydro-rosin'ester. 3 e f' The separation of the chemically differentioomponents of-the chemically modified rosins =ha's heretoforebeen practically impossible, and the various commercial products have been complex mixtures of compounds of different chemical structure. .No successful method for separating the components of such mixtures has been deerealized that such separation would be of'great value from a commercial standpoint, as Well as from a scientific standpoint.

Now, I have found that I can separate chemically modified rosins and chemically modified 4 rosin esters into their components bya method veloped in spite of the fact that it has been fully which is relatively simple, efficient and adaptable. to commercial operation. I accomplish this by to 'the art to be selective solvents for thevisible and latent color. bodies of rosin.

rosin' ester with a solvent which is a selective solvent for the color bodies of rosin, separating the ,selective solvent from theundissolved component of the modified rosin or rosin ester'and recovering the component of the modified rosin dissolved'therein, as, for example, by evaporating the selective solvent. This process can be re- .peated as many times as necessary to produce the desireds'eparation of the components. I In carrying out this method, the modified rosins or rosin esters may or may not be'first dissolved The process in accordance with this invention consists of treating a modified rosin or modified in "a-s'olvent therefor which'is immiscible with the selective solvent which is used. Ordinarily, it

willbe found convenient to use such a solvent,

particularly if the modifiedrosin or rosin ester ,treated isa'solid at the temperature of treatment. Whenit is desired to use a solvent for the modified rosin or modified rosin ester, the procedure in accordancefwitlr this invention will consist of dissolving the modified rosin or modified rosin ester in the solvent, contacting the solution so formed with a selective rosin color body solvent solution as, for examplaby evaporating the respective solvents, preferably, under reduced pres sure. This procedure may be repeated as many crystallization from suitable solvents, fractionation'under reduced pressure, contacting with an absorbent, such as, fullers earth, kieselguhr, activatedcarbon, etc. x l

The modified rosin or modified rosin ester which I'may treat in'accordance with this invention may 4 be any rosin or rosin ester which has been treated to-ti'nodif'y its chemicalstructu're, so that the resultant product is a mixture of two or more chemically difierent substances. The hydrogenation of r'osin, or a resin ester in the presence of a suitable catalyst according to methods known to the art produces sucha modified rosin or modified rosin ester. Theesterification of a hydro- Y Will hereinafter be termed Hyex rosins and genated rosin, likewise, produces-such an ester.

The polymerization of rosin or a rosin ester to increase its molecular weight and melting point by treatment with a polymerizing agent, for example, Volatile metal halides, as, boron trifiuoride, zinc chloride, stannic chloride, aluminum chloride, ferric chloride; mineral acids, as, sulfuric acid, phosphoric acid; fullers earth, hydrogen fluoride; acid salts, as sodium acid sulfate, etc.; metallic silicon; hydro fiuoroboric acid; etc., according to methods known to the art, produces such a modified rosin or modified rosin ester. Such a modified rosin ester may also be produced by esterifying a polymerized rosin.

Again, the treatment of rosin or a rosin ester With a suitable catalyst, as, for example, a hydrogenation catalyst, as nickel, nickel chromite,

platinum, palladium, etc., atan elevated temperature of, for example, from about 150 C- to about 200 C. and without reaction between the rosin or rosin ester and any added substance, to produce an intraand inter molecular rearl rangement within the hydrocarbon nucleus of.

the rosin or rosin ester with a reduction in the apparent unsaturation as disclosed in the 00- pending application of Edwin E. Littmann, Serial No. 84,877, filed June 12, 1936, produces .a modified rosin or modified rosin ester which may be treated in accordance with this invention. Such modified rosins and modified rosin esters I-Iyex rosin esters, respectively. The esterification of a I-Iyex rosinalso produces such a chemically modified rosin ester.

The modified rosins which I treat in accordancewith this invention may be any grade of modify its chemical structure so that the product is a mixture of two or more chemically different materials. The esters of the modified rosins which I treat may be produced by the esterification of modified rosins or maybe produced by the chemical modification ofordinary esters of rosins, and may be esters of either a mo'nohydricor a polyhydric alcohol. Thus, esters of rosins with monohydric alcohols, such as, for example, methanol, ethanol, propanol, butanol, amyl alcohol, cetyl alcohol, lauryl alcohol, stearyl alcohol, furfuryl alcohol, hydrofurfuryl alcohol, abietanol, hydroabietanol, phenol, benzyl alcohol, etc., or with polyhydric alcohols, such as, for example, ethylene glycol, diethylene glycol, triethylene glycol, glycerol, sorbitol, mannitol, erythritol, pentaerythritol, treated by my new method.

The selective solvent which I use in accordance with this invention maybe any of the various selective solvents for the visible and latent color bodies of rosins and rosin esters heretofore known. Thus, I may use furfural, furfuryl alcohol, a chlorohydrin, as, ethylene chlorohydrin, propylene chlorohydrin, etc., aniline, phenol, resorcinol, ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, trimethylene glycol, glycerol, butyl glycerol, ethyl formate, methyl acetate, methyl formate, methyl orthonitrobenzoate, methyl furoate, alkyl .formate, monoacetin, diacetin, triacetin, ethylene glycol monoacetate, methanol, hydroxyl alkyl amine, as, triethanolamine, a solution of oxalic acid in water or in methanol, ethanol or other lower aliphatic alcohol, ethylene glycol monoethyl ether, or other immiscible glycol ether, ethylene glycol monoacetate, or other immiscible glycol ester, methyl thiocyanate, ethyl thiocyanate,

etc., may be acetonitrile, acetic acid, acetic anhydride, pchloroaniline, resorcinol. plus hydrosulphite, ethylene glycol diacetate, glycerol diacetate, resorcinol monoacetate, resorcinol diacetate, phenyl acetate, furfuryl acetate, ethylidine diacetate, n-propyl furoate, ethylglycollate, methyl citrate, ethyl tartrate, ethyl malonate, methyl maleate, dimethyl phthalate, benzyl formate, monobutyrin, ethyl carbonate, methyl lactate, diethyl oxalate, methyl adipate, hydroxyhydroquinone triacetate, methyl chlorocarbonate, propylene glycol monoacetate, hydroquinone diacetate, catechol .monoacetate, guaiacyl acetate,

methyl glutarate, ethyl oxalate, ,benzyl acetate,

diethyl glutacoate, ethyl lactate, diethyl phthalate, ethyl anisate, methyl salicylate, methyl cinnamate, methyl mandelate, methyl acrylate,

ethyl oxamate, methyl succinate, ethyl DIOPlO'r late, methyl acrylate, ethyl malate, methoxybenzaldehyde, guaiacol, anisidin, nitroanisol, di-

chloroethyl ether, methoxy acetic acid, methyoxybenzyl alcohol, liquid sulfur dioxide, nitromethane, etc., or mixtures of such refining agents which are chemically non-reactive, etc.

The solvent in which I may dissolve'the modified rosin or modified rosin ester before con-- tacting it with a selective. solvent may be any solvent for the modified rosin or modified rosin ester which is immiscible and non-reactive with the selective, solvent used. Thus, I may use a petroleum hydrocarbon solvent, such as, for example, gasoline, petroleum ether, a normally gaseous petroleum hydrocarbon held in liquid phase by elevated pressure, low temperature, or both. The concentration of the modified rosin or modified rosin ester in such a solution may be Wood or gum resin which has been treated to within the range of about 5% to about by weight, and desirably within the. range of about 15% to about 30% by weight.

The temperature at which the process in accordance with my invention may be carried out is dependent upon the selective solvent employed and will be within the range of about 40 C. to about +60 C. In any case the temperature used will be such that the selective solvent is a liquid under the pressure used.

, In the embodiment of my process in which a. chemically modified rosin or a chemically modified rosin ester is dissolved in asolvent therefor before it is contacted with a selective solvent, thev solution so formed may have a concentration within the range of about 5% to about 40%, by weight. Usually I prefer to use a solution having a concentrationwithin the range of about 10 to about 25% by weight.

The number of washes employed in my process maybe varied in accordance with the results desired, and it will be appreciated that the greater the number of washes given the sharper will be the separation of the components of the chemically modified rosin or chemically modified rosin ester treated.

As illustrations of the practical adaptation of the method in accordance with this invention,

I may cite the following:

EXAMPLE 1 with '15 cc. of furfural, with 25 parts by volume 5 a ansor of-i urfural.- The furfural'wash solutions were combined and evaporated to recover the component of the polymerized rosin dissolved therein. Likewise, the gasoline solution was evaporated to recover the component remaining there- The 'two components thus separated from the original polymerized rosin and a sample of the original polymerized rosin were tested by making them-into core oils and observing the time required for the core oil to crystallize. The core oil' made from the original "polymerized rosin had crystallized in about 105 'days, showing it to be non-crystalline. The component of the polymerized rosin recovered.,from the gasoline solution after treatment withfurfural crystallized from core oil in five days showing it to be unpolymerized rosin. ,Onflthe other hand, the

component of the original polymerized rosin 'recovered ,from .the 'furfural had not crystallized from core oil in one hundred and forty days, as

compared with about onelhundred and five days for theoriginal polymerized rosin, showing it to be more highly-polymerized than the original rosin. hese core. oil tests demonstrate that the process in accordance vwiththis invention separated the rosin polymerized by treatment with aluminum chloride, into two components one of which is a highly polymerized and the other an ordinary unpolymerized rosin.

v EXAMPLE 2 A stock solutionwas prepared which contained 25% of rosin. The rosin present in'this solu tion was composed of Igwood. rosin and 50% Iwood-rosin hydrogenated to the extent of 50% eithe theoretical for two double bonds. There portions of this stock solution of 200 cc. each were counter-currently .washed with three portions. of 200, cc.;of.furfural at room temperature, so that the spent furfural fromthe :firststag successively passed on to stage 2 and finally stage 3. The three ".furfural washed gasoline solutions, .and the three furfural solutions, were evaporated to recover the rosin components dissolved therein. The various components thus secured were analyzed'with the results given in An inspection of the above example shows that the original blended rosinhaving a 32% hydrogenation was separated into fractions which ranged from-0.0% hydrogenation to 65.5% hydro'genation' The yields in Table I show the er cent rosin recovery from each gasoline'solution and the *perfcent recovery'from the combined furfural solutions 'of' the total rosin treated.

EXAMPLE 3 A hydrogenated I woodrosin saturated to the extent of" 60% was used in this experiment.

' Threeportions of-300 gram's'ea'ch' were countercurrently washed with five portions or. 100 cc.

each of furfural. The resulting gasoline solu-' tions and the combined furfural solutions were evaporated under reduced pressure. The products thus secured showed the following results on analysis: I I.

Table II s Refractive Hydro index i genation I r Percent Percent Original hydrogenated rosin l. 5255 60 Fraction from gasoline sol. No. 1.. 1. 5218 78 44. 5 Fraction from gasoline so]. No. 2.. 1. 5230 74 66. 2 Fraction from gasoline sol. No. 3 1. 5243 68 '81. 1

Fraction from combined iurfural fractions 1.538 I 22 An inspection of the above table shows that the furfural wash removed unhydrogenated or 1 slightly hydrogenated resin from the hydro genated rosin contained in the gasoline solution, so that the saturationofthe hydrogenated rosin recovered fromnthe gasoline solution was increased to 'as high as 78%. As acomparison it will be noted that the rosin recovered 'from the furfural was saturated to the extent only of 22%. The yields in Table II show the per cent rosinrecovery; from each gasoline solution.

ExAMPLn 4 A gasoline solution containing 13% Hyex wood rosin was prepared. Three-portions of this solu-,

' tion, each 300 parts by,- volume; were counter-- Table n I Refractive S pacific. ggs index rotation eyield Y 7 9C. Percent Original Hyex rosin. 83 1. 5426 Fraction from gasoline v i so]. 0. 1 72 1. 5375 +52. 3 17. 5 Fraction from gasoline I i I s 78 I. 5376 +53.4 22. 5 Fraction from gasoline s N0. 3 80. 5 1. 5400' +55. 4 31. 5 Fraction from aqueous Y f phenol 86.0 1.539 +61.4 21.6

An examination of the sto e tableshows that. I

the treatment separated. theioriginal Hyex rosin into two-components having quite differentphy'sis cal characteristics from:' one another. A com-'- parison of thepropertiesof the component from gasolinefsolution 3 and those, of the'component from the aqueous phenol brings; this out. Thus, the'aqueous phenol component hada definitely higher meltingpoint, a lower refractive index, and a higher specific rotati'omthan the'fraction from the gasoline solution.

.. ExAMPLnti A gasoline solution-v containing 20% Hyex rosin was prepared. Three portions of 300 parts by volume each of-the solution were counterourrently washed with one portion of furfural of fifty parts byvolume and four portions of furfural of thirty parts by volume,-so that each or the gasoline solutions received four counter-cur rent washes. The gasoline solutions and the combined furfuralwash solutions were evaporated under reduced pressure, and the properties of the rosin components 'recovereddetermined by analysis. Their characteristics are given in Table IV which follows:

Table IV Drop Acid Refrac- Specific melting N tive rota- Yield point index tion Fraction from gaso- C. I Percent llne sol. No. l 75.5 156.5 l. 5371 +500 21. 6 Fraction from gasoline so]. No. 2 77.5 160.5 1.5378 +54.5 i 25.6 Fraction from gasoline sol. No. 3. 82. G 163. 0 1. 5382 +53. 4 32. 8 Fraction from iuriural Sol 90. 0 161. 5 1 l. 5527 +60. 2 l5. 2

In the above Table Iv, as in Tate-m Deal;

ample 4, the characteristics of the separated.

components show them to be different typesof rosin.

' EXAMPLE "6 Three portions of a solution of hydrogenated I grade wood rosin ingasoline of 200 grams each were counter-currently washed with methyl thiocyanate at C.,' so that each gasoline solution received five washes with20 cc. of methyl thiocyanate. The three refined gasoline solutions and 'the combined thiocyanate solutions were evaporated under reduced pressure to re cover the'rosin fractions dissolved in each. The analyses and yields of these fractions of the hydrogenated rosin, as well as that of the original hydrogenated rosin, are given in Table V which An inspection of the data of Table V shows that the treatment with the methyl thiocyanate solution separated the hydrogenated rosin having a saturation of 62.5% of theoretical into fractions having saturations within the range of 67-72% of theoretical on one hand and 30% of theoretical on the other. Thus, the thiocyanate tended to selectively dissolve unhydrogenated rosin from the more highly hydrogenated rosin which remained in the gasoline solution.

EXAMPLE '7 Three portions of a 20% solution of dihydroabietyl alcoholjin gasoline of 50 grams each were counter-currently washed with methyl thiocyanate at 0C., so that each gasoline solution received five washes with 10 cc. portions of methyl thiocyanate. The three refined gasoline solutions and the combined thiocyanate solutions were evaporatedunder reduced pressure to .recover the dissolved fractions. The analysis and yields of these fractions of the dihydroabietyl alcohol-are given in Table VI.

Table VI Weight Hydroxyl Alcohol recovered D. H. A.

Percent Percent Grams Original dihydroabietyl alcohol 4. 81 Dihydroabietyl alcohol from gasolino sol. No. 1 4.4 43 0. 7 Dihydroabietyl alcohol from gas oline sol. No. 2 4. 65 60 2.0 Dihydroabietyl alcohol from gas oline sol. No. 3 ,4. 7 8O 11.8 Dihydroabietyl alcohol combined methyl thiocyanate sol 4. 8 91. 5 12.3

An inspection offthe data'of Table'VI shows that the original sample of dihydroabietyl alcohol was 31% alcohol, while the fraction recovered from the combined methyl t hioc'y'ana'te solution was 91.5% dihydroabietylalcohol. As compared with this, the fraction recovered in the No. 1

gasoline solution was only 75% dihydroabietyl alcohol. Thus; the treatment in accor'dancewith this invention definitely concentrated the alcoholic portion of the original dihydroabietyl alcohol in the methyl thiocyanate fraction.

ExAMPtE 8 Three portions of 100 grams each of .a 20% solution of dihydroabietyl alcohol in gasoline were washed counter-currently with aniline at 0? C., so that each gasoline solution received five washes with 10 cc. portions of aniline. The three refined gasoline'solutions and also the combined aniline solutions were evaporated under reduced pressure to recover the'dissolved products. The analyses and yieldsof these products are given in Table VII which follows:

Table "VII v "111111.. Hydroxyl Alcohol 533% recovered Percent Percent Gram: Original dihydroabietyl alcohoL... 4. 75 81 Dihydroabietyl alcohol from gasoline sol. No. 1..-, 4.4 75 9.5 Dihydroabi yl alcohol from gasoline sol. N0. 2 I 4. 65 78.5 16.5 Dihydroabietyl alcohol from gasoline sol. No. 3 4. 7 19. 2 Dihydroabietyl alcohol from combined aniline solutions 4. 75 82 ll. 3

An examination of the above data shows that aniline, like the methyl thiocyanate of the Example '7 selectively dissolved the dihydroabietyl alcohol, yielding a fraction which was materially purer than the original sample.

EXAMPLE 9 A glycerol ester of hydrogenated wood rosin (hydroabietic acid) was dissolved in gasoline to a 20% concentration. IThree portions of 200 cc. each of this 20% solutionwere countercurrently washed at 25 C. so that each portion received six washed with 20 cc. portions of 85% phenol. The three refined gasoline solutions and the combined phenol solutions were evaporated under reduced pressure. Theanalyses and yields of the fractions thus recovered are given in Table VIII.

Since it is known that the less saturated products have higher refraction indices, a comparison of the refractive index of the original ester with that of the fraction secured from the combined phenol extract shows that the latter contains less saturated material than the original, and is a definitely different material.

EXAMPLE 10 The methyl ester of hydrogenated wood rosin (dihydroabietic acid) was treated following exactly the same procedure as in Example 9 with the exception that furfural, instead of 85% phenol, was used as a selective solvent. The

analyses and yields of the recovered fractions of the ester are given in Table IX.

Table IX Refractive Saturaindex tion Y Percent Grams Original methyl hydro-abietate 1. 5177 40 Ester from gasoline sol. N o. 1 1. 5148 50 28 Ester from gasoline sol. No. 1. 5163 43 31 Ester from gasoline sol. No. 3. 1. 5164 43 38 Ester from combined furfnral ext 1. 528 22 An examination of the data given in Table IX shows that the hydrogenated abietyl ester was concentrated in the gasoline solution No. 1 while the unhydrogenated ester was concentrated in the furfural extract.

EXAMPLE 11 The glycerol ester of Hyex wood rosin was dissolved in gasoline to produce a solution. Three portions of 200 grams each of this solution were counter-currently washed with furfural at room temperature (C.) so that each portion received washes with six 20 cc. portions of furfural. The gasoline solutions and the combined furfural washes were then evaporated under reduced pressure. of the recovered products are given in Table X.

Table X Refractive index Ylem Grams Original glycerol ester of Hyex rosin; 1. 5442 Ester from gasoline sol. No. 1 1. 5432 i 25 Ester from gasoline sol. No. 2 1. 6435 38 Ester from gasoline sol. No. 3 1. 5454 39 Ester from combined furfural ext l. 552 21 A comparison of the refractive indices of the original ester, the fraction recovered from the No. l gasoline solution and the fraction recovered from the furfural solution, shows that the original ester of Hyex rosin has been separated into two chemically different fractions by the furfural wash.

It will be understood that the above examples and details of operation are given byway of il- The. analyses and yields lustration-only, and'zthat the scope of myinvention'iasiherein broadly described and claimed is in no way1imited.thereby;.

1-..Wh61f8 in theappended claims l have used the term .Hyex rosin .or; fHyex-rosin ester it will be understood.that1I mean. a rosin or a rosin ester which has been chemically modified byan interand intra-molecular rearrangement within the hydrocarbon nucleus of the rosin or rosin ester as hereinbefore described.

This application form'sa division of my application Serial No.,160,725, filed August 24, 1937 entitled Separation of chemically-modified resins and their esters into components.

What'I- claim and desire to protect by Letters Patent is:

l. The method of separating Hyex rosin into its components, which comprises dissolving Hyex rosin in a solvent therefor, contacting the solution so formed with a selective rosin color-body solvent immiscible with the said solution, separating the selective solvent therefrom and recovering a component of 'the-Hyexrosin from each of the resulting solutions.

2. The method of separating Hyex rosin into its components, which comprises dissolving Hyex rosin in a solvent therefor, contacting the solution so formed with a selective rosin color-body solvent immiscible with the said solution, separating the selective solvent therefrom and recovering a component of the Hyex rosin from each of the resulting solutions by evaporating thesolvent.

3. The method of separating Hyex rosin into its components, which comprises dissolving Hyex resin in a solvent therefor, contacting the solution so formed with furfural, separating the selective solvent therefrom and recovering a component of the Hyex rosin from each of the resulting solutions by evaporating the solvent.

4. The method of separating. Hyex rosin into its components, which comprises dissolving Hyex 'rosin in a solvent therefor, contacting the solution so formed with phenol, separating'the selective solvent therefrom and recovering a component of the Hyex rosin from each of the resulting solutions by evaporating the solvent.

5. The method of separating Hyex rosin into its components, which comprises dissolving Hyex rosin in a solvent therefor, contacting the solution so formed with an alkyl thiocyanate, separating the selective; solvent therefrom and recovering a component of the Hyex rosin from each of the resulting solutions by evaporating tacting the solution so formedwith furfural, separating the furfural therefrom and recovering a component of the Hyex rosin from each of the resulting solutions .by evaporating the solvent.

8. The 'method of separating Hyex rosin into its components, which comprises dissolving Hyex rosin in a petroleum hydrocarbon solvent, contacting the solution so formed with phenol, separating the phenol'therefrom and recovering a J tacting the solution so formed with an allay] thiocyanate, separating the alkyl 'ti'ii'ocyanate there from and recovering a component of the Hyex rosin from eaoh of the resulting solutions by evaporating the solvent.

JOSEPH N. BORGLIN. 

